package com.paad.earthquake;

import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLConnection;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.util.GregorianCalendar;
import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;
import android.app.Activity;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.location.Location;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.View;
import android.view.MenuItem;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.AdapterView.OnItemClickListener;

public class Earthquake extends Activity {

  static final private int MENU_UPDATE = Menu.FIRST;
  static final private int MENU_PREFERENCES = Menu.FIRST+1;
  static final private int QUAKE_DIALOG = 1;
  private static final int SHOW_PREFERENCES = 1;

  ListView earthquakeListView;
  ArrayAdapter<Quake> aa;
  ArrayList<Quake> earthquakes = new ArrayList<Quake>();
    
  Quake selectedQuake;
  
  int minimumMagnitude = 0;
  boolean autoUpdate = false;
  int updateFreq = 0;

  @Override
  public void onCreate(Bundle icicle) {
    super.onCreate(icicle);
    setContentView(R.layout.main);
    
    earthquakeListView = (ListView)this.findViewById(R.id.earthquakeListView);

    earthquakeListView.setOnItemClickListener(new OnItemClickListener() {
        public void onItemClick(AdapterView _av, View _v, int _index, long arg3) {
          selectedQuake = earthquakes.get(_index);
          showDialog(QUAKE_DIALOG);
        }
      });
    
    int layoutID = android.R.layout.simple_list_item_1;
    aa = new ArrayAdapter<Quake>(this, layoutID , earthquakes);
    earthquakeListView.setAdapter(aa);
 
    updateFromPreferences();
    
    //refreshEarthquakes();
  }
  
  private void refreshEarthquakes() {
	  // Get the XML
	  URL url;
	  try {
	    String quakeFeed = getString(R.string.quake_feed);
	    url = new URL(quakeFeed);
	         
	    URLConnection connection;
	    connection = url.openConnection();
	       
	    HttpURLConnection httpConnection = (HttpURLConnection)connection; 
	    int responseCode = httpConnection.getResponseCode(); 

	    if (responseCode == HttpURLConnection.HTTP_OK) { 
	      InputStream in = httpConnection.getInputStream(); 
	          
	      DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
	      DocumentBuilder db = dbf.newDocumentBuilder();

	      // Parse the earthquake feed.
	      Document dom = db.parse(in);      
	      Element docEle = dom.getDocumentElement();
	        
	      // Clear the old earthquakes
	      earthquakes.clear();
	          
	      // Get a list of each earthquake entry.
	      NodeList nl = docEle.getElementsByTagName("entry");
	      if (nl != null && nl.getLength() > 0) {
	        for (int i = 0 ; i < nl.getLength(); i++) {
	          Element entry = (Element)nl.item(i);
	          Element title = (Element)entry.getElementsByTagName("title").item(0);
	          Element g = (Element)entry.getElementsByTagName("georss:point").item(0);
	          Element when = (Element)entry.getElementsByTagName("updated").item(0);
	          Element link = (Element)entry.getElementsByTagName("link").item(0);

	          String details = title.getFirstChild().getNodeValue();
	          String hostname = "http://earthquake.usgs.gov";
	          String linkString = hostname + link.getAttribute("href");

	          String point = g.getFirstChild().getNodeValue();
	          String dt = when.getFirstChild().getNodeValue();  
	          SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd'T'hh:mm:ss'Z'");
	          Date qdate = new GregorianCalendar(0,0,0).getTime();
	          try {
	            qdate = sdf.parse(dt);
	          } catch (ParseException e) {
	            e.printStackTrace();
	          }

	          String[] location = point.split(" ");
	          Location l = new Location("dummyGPS");
	          l.setLatitude(Double.parseDouble(location[0]));
	          l.setLongitude(Double.parseDouble(location[1]));

	          String magnitudeString = details.split(" ")[1];
	          int end =  magnitudeString.length()-1;
	          double magnitude = Double.parseDouble(magnitudeString.substring(0, end));
	              
	          details = details.split(",")[1].trim();
	              
	          Quake quake = new Quake(qdate, details, l, magnitude, linkString);

	          // Process a newly found earthquake
	          addNewQuake(quake);
	        }
	      }
	    }
	  } catch (MalformedURLException e) {
	    e.printStackTrace();
	  } catch (IOException e) {
	    e.printStackTrace();
	  } catch (ParserConfigurationException e) {
	    e.printStackTrace();
	  } catch (SAXException e) {
	    e.printStackTrace();
	  }
	  finally {
	  }
	}

    private void addNewQuake(Quake _quake) {
	  if (_quake.getMagnitude() > minimumMagnitude) {
	    // Add the new quake to our list of earthquakes.
	    earthquakes.add(_quake);

	    // Notify the array adapter of a change.
	    aa.notifyDataSetChanged();
	  }
	}
    
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
      super.onCreateOptionsMenu(menu);

      menu.add(0, MENU_UPDATE, Menu.NONE, R.string.menu_update);
      menu.add(0, MENU_PREFERENCES, Menu.NONE, R.string.menu_preferences);

      return true;
    }
            
    public boolean onOptionsItemSelected(MenuItem item) {
      super.onOptionsItemSelected(item);

      switch (item.getItemId()) {
        case (MENU_UPDATE): {
          refreshEarthquakes();
          return true; 
        }
        case (MENU_PREFERENCES): {
          Intent i = new Intent(this, Preferences.class);
          startActivityForResult(i, SHOW_PREFERENCES);
          return true;
        }
      } 
      return false;
    }
    
    @Override
    public Dialog onCreateDialog(int id) {
      switch(id) {
        case (QUAKE_DIALOG) :
          LayoutInflater li = LayoutInflater.from(this);
          View quakeDetailsView = li.inflate(R.layout.quake_details, null);

          AlertDialog.Builder quakeDialog = new AlertDialog.Builder(this);
          quakeDialog.setTitle("Quake Time");
          quakeDialog.setView(quakeDetailsView);
          return quakeDialog.create();
      }
      return null;
    }

    @Override
    public void onPrepareDialog(int id, Dialog dialog) {
      switch(id) {
        case (QUAKE_DIALOG) :
          SimpleDateFormat sdf = new SimpleDateFormat("dd/MM/yyyy HH:mm:ss");
          String dateString = sdf.format(selectedQuake.getDate()); 
          String quakeText = "Magnitude " + selectedQuake.getMagnitude() + 
                             "\n" + selectedQuake.getDetails()  + "\n" +  
                             selectedQuake.getLink();

          AlertDialog quakeDialog = (AlertDialog)dialog;
          quakeDialog.setTitle(dateString);
          TextView tv = (TextView)quakeDialog.findViewById(R.id.quakeDetailsTextView);
          tv.setText(quakeText);

          break;
      }
    }
    
    private void updateFromPreferences() {
      Context context = getApplicationContext();
      SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);

      minimumMagnitude = Integer.parseInt(prefs.getString(Preferences.PREF_MIN_MAG, "0"));
      updateFreq = Integer.parseInt(prefs.getString(Preferences.PREF_UPDATE_FREQ, "0"));
      autoUpdate = prefs.getBoolean(Preferences.PREF_AUTO_UPDATE, false);
    }
    
    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
      super.onActivityResult(requestCode, resultCode, data);

      if (requestCode == SHOW_PREFERENCES)
        if (resultCode == Activity.RESULT_OK) {
          updateFromPreferences();
          refreshEarthquakes();
        } 
    }
}